When taikonaut, Zhai Zhigang, successfully retrieved a scientific test from the outside of Shenzhou-7, the Chinese space program reached a milestone in research and development of advanced space materials.

That test is made up of solid lubricant samples.

In an interview with Xinhua Sunday, leading material scientist, Liu Weimin said the shuttle carried eleven samples of three different types of lubricants.

"The sample needed to be firmly fixed outside the spacecraft during the lift-off and orbiting," said Weng Lijun, chief designer of the test.

Scientists testing lubricant film, lubricant coating and self-lubricating composite to find out how it reacts to a low-earth orbiting environment.

Lubricants are vitally important for the safety and effectiveness of spacecraft and carriers during their work, said Liu, director of the Lanzhou Institute of Chemical Physics of the Chinese Academy of Sciences (CAS).

In light of the taikonauts's limited capability during the EVA, the experiment had to be wisely schemed and the extravehicular test platform had to be designed for easy handling and retrieval of operators, said Weng.

Liu's institute as well as the CAS Institute of Opto-Electronics, came up with a test device that was able to be unlocked by one hand.

Scientists are expecting to study the exposed sample as soon as Shenzhou-7 lands.

The CAS Lanzhou Institute has been developing new lubricants for space missions for years. Starting back in the 1960s, CAS scientists invented products for China's first home-made satellites. It also had its products on the first Shenzhou space mission in 1999.

(Xinhua News Agency September 28, 2008)